Num Lock on Latitude

When ever I boot up a Dell Latitude, the Num Lock is on. This is causing problems when some of my users try to log the network since a lot of them have letters in their password that in being entered as numbers. In other words, if their password has the any of the letters, U, I, O, P, J, K, L, or M, this letter is entered as its corresponding number. For example, the letter U is being entered as the number 4. I have gone into the BIOS and have confirmed that the Num Lock is set to "Disable" but this hasn't helped.

How do I set these laptops so that the Num Lock is NOT on when and after they boot up?